Rock drilling rig



March 1, 1966 M, W R AN 3,237,462

ROCK DRILLING RIG Filed May 15, 1964. 5 Sheets-Sheet 1 rfii 5 2?... u4!? FIG.

INVENTOR MART IN WORMAN BY QM mT-MJIT ATTORNEY M. WORMAN ROCK DRILLINGRIG March 1, 1966 5 Sheets-Sheet 5 Filed May 15, 1964 FIG 3 INVENTOR.MART/IV WORMA/V ATTORNEY United States Patent M 3,237,462 RGCK DRELLENGRIG Martin Worman, Philiipsburg, Nah assignor to ingersoii- Rand(Ionrpany, New York, N.Y., a corporation of New .1 crsey Filed May 15,1964, SQ!- No. 367,681 2 Claims. (Cl. 74-99) This invention relates torock drilling rigs and particularly to mounts for supporting rockdrilling apparatus.

An example of the art to which this invention relates is the US. PatentNo. 2,975,993, issued to M. A. Beagan, Jr. March 21, 1961. This patentdescribes a prior art drill mount including a boom having an outer endportion which is rotatably mounted on the remainder of the boom and aworm and worm gear mounted on the boom for power-turning the outer endportion about the axis of the boom. This structure has the disadvantageof being prone to failure under the vibration and heavy shock loadswhich are normally encountered by rock drilling equipment.

The principal object of this invention is to provide a rock drill mountincluding a boom having an end portion which can be power-turned aboutthe boom axis and which will reliably withstand the normal vibration andshock loads of operating rock drilling equipment.

Other important objects of this invention are: to provide an economicalboom structure which can support a rock drill and power-turn the rockdrill about the axis of the boom; and to provide a lock structure forpreventing play in a rotatable end portion of a boom after the boom endportion has been turned to a desired position relative to the remainderof the boom and is being used to support operating rock drillingequipment.

The invention is described in relationship to the accompanying drawingswherein:

FIG. 1 is a perspective view of a track-laying vehicle carrying a boomincluding an embodiment of this invention;

FIG. 2 is an axial section of the end portion of the boom shown in FIG.1, this view being broken away along line AA;

PEG. 2A is an axial section showing the remainder of the boom endsection which was broken away along line AA in FIG. 2;

FIG. 3 is a section taken along line 33 of FIG. 2;

FIG. 4 is a section taken along line 44 of FIG. 2; and

FIG. 5 is an elevational View illustrating how the embodiment can beused to drill a plurality of holes located in a vertical surface andspaced along a semi-arcuate path.

The drill rig 1 shown in FIG. 1 is the crawler type and includes achassis 2 mounted on a pair of endless tracks or treads 3 riding onsuitable idler wheels 4 and driving sprockets 5. The drive sprockets 5are driven by independent air motors 6. A boom 7 is mounted on thechassis by a connection which provides for its pivoting on the chassisin both the vertical and horizontal directions. A pair of hydrauliccylinders are provided to pivot the boom in these directions. FIG. 1shows the cylinder 8 for moving the boom in the horizontal direction.

A conventional drill guide 119 is carried by the outer 7 3,237,462Patented Mar. 1, 1966 This invention involves a means for rotatablysupporting a rotatable member 14 on the outer end of the boom 7 forlimited rotation about the axis of the boom 7 and for power-turning therotatable member through its limited rotary movement. The drill guide 11is carried by the power-dump connection 13 which is mounted on the endof the rotatable member 14.

The specific construction of the rotatable member 14 and its mounting onthe end of the boom 7 is shown in FIGS. 2 and 2A. The boom 7 includes ahollow sleeve 1d forming the forward portion of the boom 7 and carryingan enlarged collar 17 fixed on its outer end. The rotatable member 14 isrotatably journalled in the collar 17 by a pair of axially spacedbearing rings or bushings 18 and 19. The outer bearing ring 19 ismounted in an annular nut 2.0 having external threads and fitting in theopen end of the collar 17 which is internally threaded to fit the nut20. The rotatable member 14 includes a diametrically enlarged portion 21which is located between the bearing sleeves 18' and 19 and hasshoulders abutting the ends of the bearing sleeves to prevent the member14 from sliding axially in the collar 17. The enlarged portion 21 of themember 14 carries a series of ratchet teeth 22 on its periphery. Thepurpose of the teeth 22' will be explained later.

A slide 24 is slidably mounted for reciprocation within the hollowsleeve 16. The slide 24 is cylindrical and freely rides on the interiorsurface of the sleeve 16. The slide 24 is fixed to the rear end of anelongated worm shaft 25 which projects forward into a hollow center 26in the rotatable member 14. The worm shaft 25 carries a set of helicallyextending splines 27 fitting in corresponding internal helical groovesformed in the rear end of the rotatable member 14. Because of theprovision of the helical splines 27 and corresponding grooves, thereciprocation of the slide 24 within the sleeve 14 causes the rotablemember 14 to rotate within the collar 17. In effect, the rear end of therotatable member 14 carrying the helical grooves acts like a nut fittingon the worm shaft 25.

The slide 24 is connected to the forward end of a piston rod 29 which ismoved back and forth by a hydraulic cylinder (not shown) housed in therear portion of the boom 7. This hydraulic cylinder is a conventional,double-acting cylinder and moves the piston rod 29 back and forth in theboom 7 as hydraulic fluid is fed to alternate ends of the cylinder inthe usual manner.

The slide 24 is pivoted on the forward end of the piston rod 29 by meansof a pin 30 which extends through both the rod 29 and the slide 24. Apair of longitudinal slots 31 are formed in the sleeve 16 and the outerends of the pin 30 project into and ride in the slots 31 to prevent theslide 24 from turning or rotating in the sleeve 16. The pin 3t) islocked in position by a pair of snap rings 32 fitting in groovesprovided in the ends of the pin outside of the sleeve 16.

It should now be apparent that the movement of the worm shaft 26 backand forth causes the rotatable member 14 to rotate about the axis of theboom 7 for a limited angle. Preferably, the splines 27 on the worm shaft25 are arranged to rotate the rotatable member 14 through an angle of atleast 180 degrees, degrees to either side of the centered position ofthe drill guide 10 shown in FIG. 1.

Means is also provided for locking the rotatable member 14 in whateverposition it may have been turned. It is necessary to lock the member 14rigidly on the boom 7 to prevent rotary play of the member 14 on theboom which might cause the mounting of the member 14 to rapidlydeteriorate due to the normal vibration caused by the operating rockdrill.

The collar 17 contains two pairs of pivoted pawls 34 and 35 for engagingthe ratchet teeth 22. The pawls 34 prevent rotation in the clockwisedirection, looking at FIG. 3, and the pawls 35 prevent rotation in acounterclockwise direction.

A fluid-operating system is provided for holding the pawls 34 and 35 intheir alternate releasing and engaging positions. This is performed byalternate fluidoperated pistons forced against the pawls 34 and 35 tomove them to the desired positions. In FIG. 3, the pistons 36 are biasedagainst the pawls to move them to a releasing position by theintroduction of fluid pressure into the passage 37. The pistons 38 areforced against the pawls to move them to locking positions engaging theteeth 22. The pistons 38 are forced against the pawls by introducingfluid pressure into the passages 39. It will be understood that theapplication of fluid pressure to either set of passages 37 or 39 will beaccompanied with a release of pressure from the other set of passages 37or 39.

Operation Before moving or rotating the rotatable member 14 on the boom'7, the locking pawls 34 and 35 are moved to a position releasing theratchet teeth 22, as shown in FIG. 3. This is carried out by introducingfluid pressure into the passage 37 and exhausting pressure from thepassage 39.

After the pawls 34 and 35 are in their releasing position, the hydrauliccylinder operating the piston rod 29 will be operated to move the slide24 in a direction which will cause the rotatable member 14 to turn tothe desired position. If the slide 24 moves forward as shown in FIG. 2,the member 14 will rotate in a counterclockwise direction looking atFIG. 3. If the slide 24 moves rear- Wardly, the member 14 turns in aclockwise direction.

When the rotatable member 14 reaches the desired position, the slide 24is stopped, by stopping the piston rod 29 connected to a hydrauliccylinder. Thereafter, the pawls 34 and 35 are returned to their lockingpositions with the ratchet teeth 22 by exhausting pressure fluid fromthe passage 37 and introducing pressure fluid to the passage 39.

FIG. 5 illustrates how the rotatable member 14 can be selectively movedto a variety of positions to position the drill guide 10 for drilling anarcuately arranged series of holes 41.

Although only a single embodiment is illustrated and described indetail, it will be understood that the invention is not limited merelyto this embodiment but contemplates other embodiments and variationswhich utilize the concepts and teachings of this invention.

Having described my invention, I claim:

1. A rock drilling rig comprising:

(a) an elongated boom;

(b) a boom end portion rotatably mounted on the outer end of said boomfor rotation about the aXis of said boom and adapted to support rockdrilling equipment;

(c) an elongated power-turning member slidably mounted within said boomand carrying on its surface a group of helically extending splines;

(d) an annular nut fixed to said boom end portion and having helicalgrooves slidably engaging said helically extending splines whereby saidnut and boom end portion is caused to rotate about said boom in responseto the axial sliding of said power-turning member in said nut;

(e) means non-rotatably connecting said power-turning member to saidboom for preventing it from rotating relative to the boom during itssliding movement;

(f) power means within said boom for selectively sliding saidpower-turning member back and forth through its slide path in said boomand stopping it at any selective position in said slide path;

(g) lock means for selectively locking said boom end portion on saidboom to prevent all rotary play in either rotary direction between saidboom end portion and said boom;

(h) said lock means including a series of teeth on said boom end portionand a plurality of pawls mounted on said boom and adapted to engage saidteeth to prevent rotary play in either rotary direction between saidboom end portion and said boom; and

(i) lock operating means operable to move said lock means to aninoperative position to unlock said boom end portion for rotation inboth rotary directions relative to said boom.

2. The rock drilling rig of claim 1 wherein:

(a) said lock operating means includes a pressure fluid system operablefor simultaneously releasing all of said pawls from said teeth.

References Cited by the Examiner UNITED STATES PATENTS BROUGHTON G.DURHAM, Primary Examiner.

D. H. THIEL, Assistant Examiner.

1. A ROCK DRILLING RIG COMPRISING: (A) AN ELONGATED BOOM; (B) A BOOM ENDPORTION ROTATABLY MOUNTED ON THE OUTER END OF SAID BOOM FOR ROTATIONABOUT THE AXIS OF SAID BOOM AND ADAPTED TO SUPPORT ROCK DRILLINGEQUIPMENT; (C) AN ELONGATED POWER-TURNING MEMBER SLIDABLY MOUNTED WITHINSAID BOOM AND CARRYING ON ITS SURFACE A GROUP OF HELICALLY EXTENDINGSPLINES; (D) AN ANNULAR NUT FIXED TO SAID BOOM END PORTION AND HAVINGHELICAL GROOVES SLIDABLY ENGAGING SAID HELICALLY EXTENDING SPLINESWHEREBY SAID NUT AND BOOM END PORTION IS CAUSED TO ROTATE ABOUT SAIDBOOM IN RESPONSE TO THE AXIAL SLIDING OF SAID POWER-TURNING MEMBER INSAID NUT; (E) MEANS NON-ROTATABLY CONNECTING SAID POWER-TURNING MEMBERTO SAID BOOM FOR PREVENTING IT FROM ROTATING RELATIVE TO THE BOOM DURINGITS SLIDING MOVEMENT;